钙对ZA85镁合金显微组织和力学性能的影响

Effect of Ca on Microstructure and Mechanical Properties of ZA85 Alloy

摘要: 研究了钙的加入对ZA85镁合金显微组织和力学性能的影响.结果表明：当ZA85镁合金中钙质量分数为0.3%~0.9%时,钙元素均固溶于基体中,合金中无含钙相生成;随钙含量增加,力学性能提高,当钙质量分数为0.6%时,铸态合金的显微硬度和室温抗拉强度达到最大值117.5 HV和164 MPa,150 ℃时的抗拉强度为149.5 MPa;经300 ℃×24 h均匀化处理后,其150 ℃时的抗拉强度提高到159.2 MPa;室温拉伸断口主要由解理面组成,呈脆性断裂;高温断口解理面减少,韧窝增大,呈韧性断裂.

Abstract: The effect of calcium on microstructure,mechanical properties of ZA85 alloy was studied.When the addition of Ca is 0.3％-0.9%,new phases do not form.Mechanical properties can be improved with increasing of the content of calcium,when the addition is 0.6%,the microhardness and ultimate strength increase to 117.5 HV and 164 MPa.The ultimate strength of casting alloy with an addition of 0.6% Ca is 149.5 MPa at 150 ℃ and the ultimate strength increase to 159.2 MPa after homogenizing treatment at 300 ℃ for 24 h.The morphology of room temperature fracture is brittle fracture and mainly consiste of planes.The planes decrease and ductile sockets increase at high temperatures,the fracture is ductile rupture.